The IP Multimedia Subsystem (IMS) is an open and standardized architecture for converged fixed and mobile communications services. IMS enables service providers to expand their offerings to their customers by integrating voice and multimedia communications, such as video, text, images and instant messages, and delivering them into new environments. It is well known that IMS is emerging as a viable architecture that potentially may enable the convergence of various forms of communication, including voice and data, fixed and mobile services, public hot spot and enterprise WLAN, into an immersive system to provide the user with a seamless experience across various access networks.
A private branch exchange (PBX) is well known throughout the telecommunications industry. A PBX is a telephone exchange system that serves a particular business or office. A PBX connects the internal telephones of a private organization, usually a business, to the public switched telephone network (PSTN). The PSTN is a circuit switched network in which calls are assigned dedicated circuits during the duration of the call. Voice over Internet Protocol (VoIP) is a protocol optimized for the transmission of voice through the Internet or other packet-switched networks. An Internet Protocol PBX (IP-PBX) is a system designed to deliver voice over a data network and interoperate with the PSTN by combining VoIP gateways with traditional PBX functionality.
Many of the current IMS standards and enriched services were originally designed for the individual subscribers that are serviced by a wireless network such as a Wi-Fi or a cellular network. Although the IMS standards are expanding to support wireline services, including PBXs, these efforts only address the PBX as a single entity. IMS data network services are not available to many individual devices that are connected to the PBX. These PBX users are served by the PBX and not the IMS data network. Thus, the IMS standards do not fully address the problem of providing the IMS enriched services and features to individual users connected to a PBX.
What is needed is a method for providing IMS enriched services and features to users connected to a PBX or an IP-PBX.